Lifting-jack.



No. 743,260. 7 PATENTED NOV. s, 1903.

F. DURGIN.

LIFTING JACK.

APPLIOATION FILED MAR. 17, 1903.

- TH: Norms Finns co, PndTou'mol WASNINGYO'L a. c.

UNITED STATES Patented November 3, 1903.

PATENT OFFICE.

FRANK DURGIN, OF LEMARS, IOWA.

SPECIFICATION formingpart of Letters Patent N 0. 743,260, dated November 3, 1903.

7 Application filed March 17, 1903. Serial No. 148,252. (No model.)

To 60% whom it may concern:

Be it known that I, FRANK DURGIN, a citizen of the United States, residing in the city of Lemars, in the county of Plymouth and State of Iowa, have invented certain new and useful Improvements in Lifting -Jacks, of which the following is a specification.

This invention relates to lifting-jacks and it has for its object to improve the construction of jacks now in use.

Other objects and advantages will appear in the following description and will be pointed out in the claims.

In the drawing thefigure is a perspective View of my invention, partly in section.

In a hollow standard A, provided with a base 0 and a vertically-elongated slot D, is a verticallymovable lifting box B, having a head N and a plurality of notches G H I J K L, having their upper walls in a horizontal plane. Surrounding the standard A near its upper end is a collar 0, formed of a band, the ends of which are spread apart and project laterally from the standard A. Pivoted between the projecting end of the band C at P is a dog E, one end of which projects above the band, and the other end is provided with an upwardly-extending point, the lower face of which is straight. Also pivoted to the projecting ends of the band (J at R in front of the pivoted dog E is a pair of links Q, between the free end of which is fulcrumed intermediate its ends a lever M, which is provided with an upwardly-curved engaging end F, adapted to enter the notches G H I J K L to elevate the lifting-bar B. When it is desired to lower the lifting-bar, the upwardlycurved end F of the lever M is forced against the lower straight face of dog E, and by reason of the horizontal upper walls of the notch in which the dog is held the dog, is permitted to slide out of the notch and the lifting-bar drops of its own weight. The end F of the lever is curved upwardly, so that when the lever M is thrown to its lowermost position it will not strike the surface upon which the jack rests.

Having described my invention, what I claim is-- r 1. A lifting-jack comprising a standard, a lifting-bar movable vertically upon the standard and provided with notches having horizontal upper walls, a collar supported by the standard, a dog pivoted to the collar and having an upwardly-extending projection with a lower straight 'face, links supported by the collar, a lever 15 ulcru med intermediate its end to the links and having an upwardly-curved end adapted to be moved into engagement with the lower straight face of the upwardlyextending projection on the engaging dog to move it from a notch in the lifting-bar.

2. Alifting-jackcomprisingahollowstandard provided with a vertically-elongated slot, a lifting-bar movable vertically in the standard and provided with notches having horizontal upper walls, a band surrounding the standard at its upper end and having its ends projecting laterally therefrom, a dog pivoted between the projecting ends of the band and having an upwardly-projecting end provided with a lower straight face, a pair of links pivoted to the projecting ends of the band in front of the dog, a lever fulcrumed intermediate its ends between the links, and having an upwardly-curved end adapted to be moved into engagement with the lower straight face of the upwardly-extending projection on the engaging dog to move it from a notch in the lifting-bar.

' FRANK DURGIN.

Witnesses:

. T. M. ZINK,

MARGARET OAHooN. 

